Solid state electronics relies on the intentional introduction of impurity atoms or dopants into a semiconductor crystal and/or the formation of junctions between different materials (heterojunctions) to create rectifiers, potential barriers, and conducting pathways. With these building blocks, switching and amplification of electrical currents and voltages are achieved. As miniaturisation continues to ultra-scaled transistors with critical dimensions on the order of ten atomic lengths, the concept of doping to form junctions fails and forming heterojunctions becomes extremely difficult. Here, it is shown that it is not needed to introduce dopant atoms nor is a heterojunction required to achieve the fundamental electronic function of current rectification. Ideal diode behavior or rectification is achieved solely by manipulation of quantum confinement using approximately 2 nm thick films consisting of a single atomic element, the semimetal bismuth. Crucially for nanoelectronics, this...

Density functional theory paired with a first order many-body perturbation theory correction is applied to determine formation energies and charge transition energies for point defects in bulk In0.53Ga0.47As and for models of the In0.53Ga0.47As surface saturated with a monolayer of Al2O3. The results are consistent with previous computational studies that AsGa antisites are candidates for defects observed in capacitance voltage measurements on metal-oxide-semiconductor capacitors, as the AsGa antisite introduces energy states near the valence band maximum and near the middle of the energy bandgap. However, substantial broadening in the distribution of the GaAs charge transition levels due to the variation in the local chemical environment resulting from alloying on the cation (In/Ga) sublattice is found, whereas this effect is absent for AsGa antisites. Also, charge transition energy levels are found to vary based on proximity to the semiconductor/oxide interfacial layer. The combin...

The full text of this article will not be available in ULIR until the embargo expires on the 29/03/2019Pyroelectricity is the ability of certain non-centrosymmetric materials to generate an electric chargein response to a change in temperature and finds use in a range of applications from burglar alarms to thermal imaging. Some biological materials also exhibit pyroelectricity but the examples of the effect are limited to fibrous proteins, polypeptides, and tissues and organs of animals and plants. Here, we report pyroelectricity in polycrystalline aggregate films of lysozyme, a globular protein

<p>This article is available at https://link.springer.com/</p><p>Glioblastoma (GBM) is an aggressive brain tumour, associated with extremely poor prognosis and although there have been therapeutic advances, treatment options remain limited. This review focuses on the use of immunotherapy, harnessing the power of the host's immune system to reject cancer cells. Key challenges in glioma specific immunotherapy as with many other cancers are the limited immunogenicity of the cancer cells and the immunosuppressive environment of the tumour. Although specific antigens have been identified in several cancers; brain tumours, such as GBM, are considered poorly immunogenic. However, as detailed in this review, strategies aimed at circumventing these challenges are showing promise for GBM treatment; including identification of glioma specific antigens and endogenous immune cell activation in an attempt to overcome the immunosuppressive environment which is associate...

<p>This article is available from https://www.nature.com</p><p>Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility...

In this work, we present a detailed analysis of the second-order piezoelectric effect in c-plane InxGa1xN/GaN quantum dots and its consequences for electronic and optical properties of these systems. Special attention is paid to the impact of increasing In content x on the results. We find that in general the second-order piezoelectric effect leads to an increase in the electrostatic built-in field. Furthermore, our results show that for an In content 30%, this increase in the built-in field has a significant effect on the emission wavelength and the radiative lifetimes. For instance, at 40% In, the radiative lifetime is more than doubled when taking second-order piezoelectricity into account. Overall, our calculations reveal that when designing and describing the electronic and optical properties of c-plane InxGa1xN/GaN quantum dot based light emitters with high In contents, second-order piezoelectric effects cannot be neglected.

<p>The original article is available at<a href="http://jcs.biologists.org"> http://jcs.biologists.org</a></p><p>Targeting the proteasome is a valuable approach for cancer therapy, potentially limited by pro-survival pathways that are induced in parallel to cell death. Whether these pro-survival pathways are activated in all cells, show different activation kinetics in sensitive versus resistant cells or interact functionally with cell death pathways is unknown. We monitored activation of the heat-shock response (HSR), a key survival pathway induced by proteasome inhibition, relative to apoptosis activation in HCT116 colon cancer cells expressing enhanced green fluorescent protein (EGFP) under the control of the HSP70 promoter. Single-cell and high-content time-lapse imaging of epoxomicin treatment revealed that neither basal activity nor the time of onset of the HSR differed between resistant and sensitive populations. However, resistant ...

Turbulence within the ocean surface boundary layer (OSBL) is an important
quantity for many processes as it mixes the ocean and transports various
ocean quantities such as pollutants, heat, and dissolved gases. However,
direct observations of the dissipation rate of turbulent kinetic energy \epsilon under
open ocean conditions are limited. Consequently, our understanding on how
to model turbulence and its related processes is constrained.
Open ocean measurements from the Air-Sea Interaction Profiler (ASIP)
from five cruises are combined with ship-based meteorological information,
direct measurements of air-sea gas fluxes, and wave data from dedicated runs
of the ECWAM wave model. This comprehensive data set allowed for an
evaluation of commonly applied approaches to scale profiles of \epsilon, as well as
to formulate a scaling relationship. During daytime conditions a relationship
based on the friction velocity and wave age describes the observations best.
During conditions when co...

Reaction cycles for the atomic layer deposition (ALD) of metals are presented, based on the incomplete data that exist about their chemical mechanisms, particularly from density functional theory (DFT) calculations. ALD requires self-limiting adsorption of each precursor, which results from exhaustion of adsorbates from previous ALD pulses and possibly from inactivation of the substrate through adsorption itself. Where the latter reaction does not take place, an “abbreviated cycle” still gives self-limiting ALD, but at a much reduced rate of deposition. Here, for example, ALD growth rates are estimated for abbreviated cycles in H2-based ALD of metals. A wide variety of other processes for the ALD of metals are also outlined and then classified according to which a reagent supplies electrons for reduction of the metal. Detailed results on computing the mechanism of copper ALD by transmetallation are summarized and shown to be consistent with experimental growth rates. Potential route...

The angular wavelet analysis is applied for assessing the spatial distribution of breakdown spots in Pt/HfO2/Pt capacitors with areas ranging from 104 to 105 μm2. The breakdown spot lateral sizes are in the range from 1 to 3 μm, and they appear distributed on the top metal electrode as a point pattern. The spots are generated by ramped and constant voltage stresses and are the consequence of microexplosions caused by the formation of shorts spanning the dielectric film. This kind of pattern was analyzed in the past using the conventional spatial analysis tools such as intensity plots, distance histograms, pair correlation function, and nearest neighbours. Here, we show that the wavelet analysis offers an alternative and complementary method for testing whether or not the failure site distribution departs from a complete spatial randomness process in the angular domain. The effect of using different wavelet functions, such as the Haar, Sine, French top hat, Mexican hat, and Morlet, a...

<p>The original article is available at https://www.nature.com</p><p>Apoptosis resistance contributes to treatment failure in colorectal cancer (CRC). New treatments that reinstate apoptosis competency have potential to improve patient outcome but require predictive biomarkers to target them to responsive patient populations. Inhibitor of apoptosis proteins (IAPs) suppress apoptosis, contributing to drug resistance; IAP antagonists such as TL32711 have therefore been developed. We developed a systems biology approach for predicting response of CRC cells to chemotherapy and TL32711 combinations in vitro and in vivo. CRC cells responded poorly to TL32711 monotherapy in vitro; however, co-treatment with 5-fluorouracil (5-FU) and oxaliplatin enhanced TL32711-induced apoptosis. Notably, cells from genetically identical populations responded highly heterogeneously, with caspases being activated both upstream and downstream of mitochondrial outer membrane permeabilis...

Modern maintenance methods are dependent upon understanding and monitoring component degradation; however, many industrial situations exist where monitoring is impossible, and component degradation mechanisms are not well understood. This research explored the hypothesis that data to support maintenance operations may be extracted within industrial situations where pre-existing data on component degradation is scarce and understanding of the physics of the degradation process is low. In order to investigate this hypothesis, a case-study in the biopharmaceutical industry was followed which attempted to discover the significant variables leading to component degradation. In such industrial scenarios, data fusion techniques, where multiple data sources are pooled together, are necessary to adequately model complex manufacturing systems. In addition, the interaction between humans and the system is an important consideration that should be taken into account. In order to develop models ...

As a device, the laser is an elegant conglomerate of elementary physical theories and state-of-the-art techniques ranging from quantum mechanics, thermal and statistical physics, material growth and non-linear mathematics. The laser has been a commercial success in medicine and telecommunication while driving the development of highly optimised devices specifically designed for a plethora of uses. Due to their low-cost and large-scale predictability many aspects of modern life would not function without the lasers. However, the laser is also a window into a system that is strongly emulated by non-linear mathematical systems and are an exceptional apparatus in the development of non-linear dynamics and is often used in the teaching of non-trivial mathematics. While single-mode semiconductor lasers have been well studied, a unified comparison of single and two-mode lasers is still needed to extend the knowledge of semiconductor lasers, as well as testing the limits of current model. S...

Mathematical analysis is an essential tool for the successful development and operation of wave energy converters (WECs). Mathematical models of moorings systems are therefore a requisite in the overall techno-economic design and operation of floating WECs. Mooring models (MMs) can be applied to a range of areas, such as WEC simulation, performance evaluation and optimisation, control design and implementation, extreme load calculation, mooring line fatigue life evaluation, mooring design, and array layout optimisation. The mathematical modelling of mooring systems is a venture from physics to numerics, and as such, there are a broad range of details to consider when applying MMs to WEC analysis. A large body of work exists on MMs, developed within other related ocean engineering fields, due to the common requirement of mooring floating bodies, such as vessels and offshore oil and gas platforms. This paper reviews the mathematical modelling of the mooring systems for WECs, detailing...

POLLEN is an interactive 3D audio/visual installation for
any number of computers connected to the network. Specifically designed for
large computer Labs, it aims at the regeneration of those spaces through the
creation of a fully immersive multimedia art installation. 3D World A 3D
physics emulator library has been integrated into the 3D virtual world enabling
pollen to collide and freely y/bounce around. The four delimiting walls are fitted with narrow slits
enabling the pollen to y/bounce onto the adjacent computers
(left/right/front/behind)
When the user move or pass in front of a computer the camera
detects the movement triggering a small "earthquake" into the virtual
environment, thus enabling the pollen to freely move as lifted in the wind.
Multichannel Audio.PUBLISHEDpeer-reviewed

This focus issue addresses some of the cutting edge research themes in many processes that occur at the interface between a semiconductor and a solution. This interface, a pH and redox potential-controlled liquid analog to the metal-semiconductor interface, is where semiconductor electrochemistry occurs. With the advent of alternative approaches to lower cost and more efficient hydrogen production, to the energetics of the electrolyte-material interface for batteries, the physics and electrochemistry of solar photovoltaics, and transistor-based technologies that monitor liquid-based biological interactions and so much more, this interface remains central to the underlying mechanisms for so many multidisciplinary topics. Energy storage and conversion, materials design and characterization, environmental science and technology, and much more, rely on this critical interface as part of the scientific search for a sustainable energy future.

With the continuous shrinkage of the footprint of inductors and transformers in modern power supplies, higher flux, while still low-loss metallic replacements of traditional ferrite materials are becoming an intriguing alternative. One candidate replacement strategy is based on amorphous CoFeBSi soft-magnetic alloys, in their metallic glass form. Here the structural and magnetic properties of two different families of CoFeBSi-based soft magnetic alloys, prepared by arc-melting and subsequent melt spinning (rapid quenching) are presented, targeting potential applications at effective frequencies of 100 kHz and beyond. The nominal alloy compositions are Co67Fe4B11Si16Mo2 representing commercial Vitrovac and Co72-xFexB28-y (where B includes non-magnetic elements such as Boron, Silicon etc. x varies between 4 and 5 % and y is varied from 0 to 2 %) denoted Alloy #1 and prepared as a possible higher performance alternative, i.e. lower power loss and lower coercivity, to commercial Vitrova...

<p>The original article is available at <a href="https://www.biomedcentral.com">www.biomedcentral.com</a></p><p><strong>Background:</strong> Chronic pro-inflammatory signaling propagates damage to neural tissue and affects the rate of disease progression. Increased activation of Toll-like receptors (TLRs), master regulators of the innate immune response, is implicated in the etiology of several neuropathologies including amyotrophic lateral sclerosis, Alzheimer’s disease, and Parkinson’s disease. Previously, we identified that the Bcl-2 family protein BH3-interacting domain death agonist (Bid) potentiates the TLR4-NF-κB pro-inflammatory response in glia, and specifically characterized an interaction between Bid and TNF receptor associated factor 6 (TRAF6) in microglia in response to TLR4 activation.</p>
<p><strong>Methods:</strong> We assessed the activation of mitogen-activated protein kinase (MAPK) an...

In this paper, we propose a modulation technique for passive optical networks that harnesses two-dimensional prime hop system optical code division multiplexing access (OCDMA) and optical orthogonal frequency-division multiplexing (OFDM) for intensity modulation with direct-detection (IMDD) to enhance users’ signal capacity in a cost-effective manner. The theoretical analysis is built from an analytical formula that takes into account both multiple-access interference and photodetector noise. Results show that OFDM-OCDMA with multiple users has similar performance to single-user conventional OOFDM for low transmitted powers.

Solution processed metal oxide thin films are important for modern optoelectronic devices ranging from thin film transistors to photovoltaics and for functional optical coatings. Solution processed techniques such as dip-coating, allow thin films to be rapidly deposited over a large range of surfaces including curved, flexible or plastic substrates without extensive processing of comparative vapour or physical deposition methods. To increase the effectiveness and versatility of dip-coated thin films, alterations to commonly used precursors can be made that facilitate controlled thin film deposition. The effects of polymer assisted deposition and changes in solvent-alkoxide dilution on the morphology, structure, optoelectronic properties and crystallinity of vanadium pentoxide thin films was studied using a dip-coating method using a substrate withdrawal speed within the fast-rate draining regime. The formation of sub-100 nm thin films could be achieved rapidly from dilute alkoxide b...

The electrochemical behaviour of MnO2 nanorod and Super P carbon based Li-O2 battery cathodes in water-containing sulfolane and anhydrous DMSO electrolytes are shown to be linked to specific discharge product formation. During discharge, large layered spherical agglomerates of LiOH were characteristically formed on the MnO2 cathodes while smaller, toroidal, spherical Li2O2 particles and films were formed on the Super P cathodes. In an anhydrous DMSO based electrolyte the LiOH structures were also found on cathodes discharged in the anhydrous electrolyte, suggesting that MnO2 initiates electrochemical decomposition of the DMSO electrolyte to form LiOH via H2O reactions with Li2O2. The LiOH crystals are uniquely formed on MnO2, and segregated to this phase even in mixed oxide-carbon cathodes. In contrast, no Li2O2 toroids were noted on Super P cathodes discharged in the DMSO based electrolytes. Instead, the morphology varied from smaller sheets (at high discharge current) to much larg...

The understanding of the mechanisms of macropore formation in p-type Si with respect to modulation of the pore diameter is still in its infancy. In the present work, macropores with significantly modulated diameters have been produced electrochemically in p-type Si. The effect of the current density and the amount of surfactant in the etching solution are shown to influence the modulation in pore diameter and morphology. Data obtained during the etching process by in situ FFT impedance spectroscopy correlate the pore diameter variation with certain time constants found in the kinetics of the dissolution process. Raman scattering and electron microscopy confirm the mesoscopic structure and roughening of the pore walls. Spectroscopic and microscopic methods confirm that the pore wall morphology is correlated with the conditions of pore modulation.

Density functional theory is used to investigate the reactivity, reduction and effect of electrolyte additives such as fluoroethylene carbonate (FEC), lithium bis(oxalate) borate (LiBOB) and lithium difluoro(oxalato) borate (LiDFOB) in propylene carbonate (PC)-based Li-ion battery electrolytes. The structural, thermodynamical and calculated infra-red vibrational analyses indicate that FEC additives reduce prior to PC, providing stable SEI film formation near the graphite anode. The reduction and reaction mechanisms of LiBOB and LiDFOB influence the SEI film composition at the graphite surface. These additives contribute to stable SEI film formation without degradation of the anode structure by PC co-intercalation.

THESEUS is a space mission concept aimed at exploiting Gamma-Ray Bursts for investigating the early Universe and at providing a substantial advancement of multi-messenger and time-domain astrophysics. These goals will be achieved through a unique combination of instruments allowing GRB and X-ray transient detection over a broad field of view (more than 1sr) with 0.5–1 arcmin localization, an energy band extending from several MeV down to 0.3 keV and high sensitivity to transient sources in the soft X-ray domain, as well as on-board prompt (few minutes) follow-up with a 0.7 m class IR telescope with both imaging and spectroscopic capabilities. THESEUS will be perfectly suited for addressing the main open issues in cosmology such as, e.g., star formation rate and metallicity evolution of the inter-stellar and intra-galactic medium up to redshift 10, signatures of Pop III stars, sources and physics of re-ionization, and the faint end of the galaxy luminosity function. In addition, it w...

Rechargeable Li–air (henceforth referred to as Li–O2) batteries provide theoretical capacities that are ten times higher than that of current Li-ion batteries, which could enable the driving range of an electric vehicle to be comparable to that of gasoline vehicles. These high energy densities in Li–O2 batteries result from the atypical battery architecture which consists of an air (O2) cathode and a pure lithium metal anode. However, hurdles to their widespread use abound with issues at the cathode (relating to electrocatalysis and cathode decomposition), lithium metal anode (high reactivity towards moisture) and due to electrolyte decomposition. This review focuses on the key scientific challenges in the development of rechargeable non-aqueous Li–O2 batteries from both experimental and theoretical findings. This dual approach allows insight into future research directions to be provided and highlights the importance of combining theoretical and experimental approaches in the optim...